Reflow soldering is widely used in the semiconductor industry to attach surface mount electronic devices to a circuit board. At the beginning of a reflow process, a solder paste (a sticky mixture of powered solder and flux) is applied to areas of the circuit board that require soldering so as to temporarily attach the electronic devices, via the solder contact pads of the electronic devices, to the circuit board. Thereafter, the entire assembly is subjected to controlled heat, which melts the solder contact pads to form the solder joints that permanently connect the electronic devices to the circuit board.
The heat used to melt the solder contact pads during a reflow process can potentially cause the semiconductor chips inside the electronic devices to experience thermal shock for a short period of time. If the electronic devices are memory storage devices, the thermal shock that occurred during a reflow process could reduce data retention that creates threshold voltage shifts for the memory chips. Even worse, when the memory chips of the memory storage device are programmed with a fast programming speed, the thermal shock to memory chips may also damage the data structure of the memory chips, leading to preloaded data corruption. One way to have good resiliency to preloaded data during a reflow process is to slow down the programming speed of the memory chips in the memory storage device. However, the slow programming speed will compromise the performance of the memory storage device, especially when the memory chips in the memory storage device do not contain any preloaded data.
It is within this context that the present invention arises.